Community leader Judge John Grey, who operates a ranch in Idaho to rehabilitate wayward boys, crusades to close a gambling establishment owned by Belle Bonner. One evening, Grey throws a party to celebrate his daughter Terry's birthday, and while Terry is turning down the marriage proposals of Rangers Roy Rogers and Bob, Grey is confronted by Belle. She offers to fund Grey's efforts to help the boys if he will leave her alone, but he refuses her offer. After Belle leaves, Grey is still in his office when criminals Spike Madagan and Duke Springer enter through the back door. Unknown to Terry or any of Grey's friends, Grey is a reformed bank robber named Tom Allison. Madagan and Springer, his former partners, threaten to reveal his past if Grey does not help them hide from their pursuers, for they have just committed a robbery and murder, but Grey refuses, saying he is not afraid of Terry finding out that he is an ex-convict. The pair knock him out and escape, and upon reaching Belle's casino, tell her about Grey's identity. The next day, Grey is confronted again by Belle, but despite her threat to tell the townspeople about him, Grey urges the town council to close her casino. Belle then instructs Springer and Madagan to hold up the local bank and plant evidence to implicate Grey. A bystander is killed during the robbery, which is quickly blamed on Tom Allison. Grey confesses his past to Roy but swears that although he does not have an alibi, he is not the culprit in this case. Roy promises to procure evidence of Belle, Madagan and Springer's guilt, but Grey's past is nonetheless revealed by Terry, who was trying to catch Allison in order to use the reward money for the boys. Roy quits the Rangers when Bob refuses to listen to his protests and arrests Grey. Roy then rescues Grey from a lynch mob arranged by Belle and her men, and with the aid of Frog Millhouse, one of Grey's ranch hands, discovers that the gang is going to steal a payroll shipment and blame the judge. After Frog and Grey, who have been captured by the gang, are taken to the robbery site, Roy persuades Bob to help him foil the theft. They are joined by a posse consisting of Terry and her young charges, and succeed in stopping the crime and rescuing Grey and Frog. Roy then captures the fleeing Springer and Madagan, who along with Belle, are later convicted of robbery and murder. During a celebratory party, Bob and Grey are reconciled, and Terry finally accepts Roy's marriage proposal.

"Idaho," music and lyrics by Jesse Stone; "Lone Buckaroo" and "Stop," music and lyrics by Bob Nolan; "Don Juan," music and lyrics by Tim Spencer; "Home on the Range," music by Dr. Brewster M. Higley, lyrics by Daniel E. Kelly; "Holy, Holy, Holy! Lord Almighty," based on "Nicaea," music by John Bacchus Dykes, lyrics by Reginald Heber; "Whoopee Ti-Yi-Yo, Git Along Little Dogies," traditional.

According to HR news items, the rights to Jesse Stone's song "Idaho" were originally bought by Republic for a film about the state's history, which was to star John Wayne. Other HR news items reported that although the studio wanted to film the picture on location in Idaho, the plan was abandoned due to "extreme uncertainty of transportation [due to wartime shortages], accomodations, the closing of Sun Valley...and the exceptionally heavy snowfall in the northern mountains." The picture was instead photographed in Kernville, CA. Modern sources include James Bush in the cast.

The American Film Institute is grateful to Sir Paul Getty KBE and the Sir Paul Getty KBE Estate for their dedication to the art of the moving image and their support for the AFI Catalog of Feature Films and without whose support AFI would not have been able to achieve this historical landmark in this epic scholarly endeavor.